Thursday, July 17, 2008

Bats, Bunkers, & Beaches

Sulfur Cinquefoil is a member of the wild rose family, but fortunately without the thorns. Since it's an insidious invasive, we spent a good portion of last week sweeping through tall grasses and treating any we found with Garlon. Spot treatments like this are time consuming, but effective to wipe out a mild infestation. There is a native version called Silver Cinquefoil that grows in many of the same habitat, so we have to keep a sharp eye to distinguish the good from the bad.

Last Wednesday evening, my coworker Brian and I met with Greg along the banks of Muck Creek to set up mist nets. We had to race the setting sun to get the nets up, which required being very careful not to snag the fragile nets into the blackberry bushes, fir trees, or other hazards. One net was 20' tall and designed much like a pair of sailboat masts, with halyards and sheets. The extra height of that net is designed to catch different species of bats, and it worked as intended, catching us a Big Brown Bat. Greg was hoping for a Hoary or Silver-furred bat, but we had no such luck. Handling the bats requires a very skilled hand to both untangle them from the nets and avoid hurting the delicate wings -- even while being bitten! Since being bitten is difficult to avoid, having rabies shots is also a prerequisite for bat handling, so Greg did this difficult work while Brian and I manned the "sails".

Our plan was to set up the one tall net and two short nets across the creek, with Greg hoping to catch about 15 bats in 3 hours. We had some troubles setting up the 2nd net, so daylight began fading fast. We had just started unpacking the 3rd net when we realized there were 3 bats already caught! As Greg worked to release the bats, more would get caught around us, so we had to close the net down after catching 15 bats in the first 30 minutes, so we could process these bats and get them flying as soon as possible, since these little bug-eating machines have fast metabolisms and need to eat each night to keep their energy level high.

Most of the bats we caught were Little Brown Yuma Bats, which are very feisty animals given their size -- an
average weight of just 7 grams! We did catch one other small species of bat in the short net, the California Myotis. Myotis is a common genus that are commonly known as the Mouse-eared bats. Processing the bats is a series of measurements and observations to report their weight, fore-arm length, gender, breeding status, color, and overall health. Bats are not usually banded since there is concern that it mat impact their fitness, but some Myotis bats with bands have been known to live over 15 years since banding. I found it very surprising such a small, intense little animal lives so long. One last observation Greg makes is a sound recording of the "Search Phase Calls", which are the ultrasonic chirps bats make to locate objects in the dark. The sounds we hear from bats are usually alarm calls, which are often a series of rapid-fire squeaks. The ultrasound is too high frequency to hear, but recording the sound and lowering it's frequency to the human range for playback was very interesting to hear. It is also a very important clue to identify the species, since many Myotis species are almost impossible to distinguish, even for an expert like Greg.

Our weekend adventure was going south to the Oregon coast to see the famous Haystack Rock. Lisa had read that the Tufted Puffins are only visiting the Rock for a few more weeks before heading further offshore for their late summer feeding grounds. We had never seen one, so it was one of our goals for the summer. Nearly all photos I'd seen of Haystack was standing alone against the rugged coastline, so we were really surprised to see it surrounded by the coastal village of Cannon Beach. The beach was very crowded on a nice, warm summer day, but the birds were protected on their rocky outpost, so it was a perfect place to view so much wildlife amidst a busy crowd of folks. We saw many birds flying and diving and nesting on the cliffs (our lifelist birds are in bold): Western, California, and Heerman Gulls, Brown Pelicans, Caspian Terns, Pelagic Cormorants, Harlequin Ducks, Tufted Puffins, Common Murres, and Pigeon Guillemots. We hiked trails up and around many of the rocky headlands, through old growth forests. Near one footbridge, we saw a pair of Rough Skinned Newts, my first salamanders to ever see in the wild. Nearby, we saw a large Gartersnake, one of the very few animals immune to their deadly poison.

One the return trip home, we stopped by infamous Cape Disappointment. It was classic Pacific Northwest coast, with craggy, rocky cliffs with a cold fog being blown over a dark forest. We visited the North Head lighthouse, haunted by the wife of the first lightkeeper who, unable to stand the howling wind, jumped off the cliff after 25 winters in the foggiest spot in America (165 foggy days per year), and the windiest lighthouse on the west coast. We huddled next to the heaters inside the lighthouse trying to remind ourselves it was mid-July, and we explored the small museum and stairs to see the fog above. Some of the trails approximate routes that were taken by the Lewis and Clark Discovery Corps, with the coast below called The Graveyard of the Pacific, and the ruins of Fort Canby make this area steeped in history as well as an interesting fog-fed rain forest. Lewis and Clark had found whales, grizzly bears, and even condors on this coast when they visited 200 years ago, but those species are no longer to be seen here - so we approximate their footsteps not just in geography, but also in biology. We found a dead Harbour seal pup on the beach, and another dead elk fawn in the forest above, so this is a harsh climate for animals as well as people. Some trails meandered through the dripping ferny forest to some massive bunkers built to protect the coast in WWII. It was a great end to a short weekend.


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